Combining recurring and non-recurring payments

Combining recurring and non-recurring payments

I am setting up an account for a non-profit that has membership packages that are billed annually and that they would like to have auto-renew each year. They would also like to give the option of including a non-recurring donation when people sign up for a membership.

How do I setup recurring memberships and non-recurring donations on the same form? And is it even possible?